<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
        .content {
            overflow: hidden;
            padding: 0 200px 0 200px;
        }
        .middle,
        .left,
        .right {
            float: left;
            position: relative;
        }
        .middle {
            width: 100%;
            height: 200px;
            background-color: aqua;
        }
        .left {
            width: 200px;
            height: 200px;
            /*? 正常情况下 他会在盒子content下面开始继续排列 而盒子存在padding 所以需要left把他顶到最左*/
            left: -200px;
            /*? 然后通过-100%顶到上一行的最左*/
            margin-left: -100%;
            background-color: blue;
        }
        .right {
            width: 200px;
            height: 200px;
            /*? 同理 顶到最左*/
            margin-left: -200px;
            /*? 顶到上一行最右*/
            right: -200px;
            background-color: brown;
        }
    </style>
</head>
<body>
<div class="content">
    <div class="middle"></div>
    <div class="left"></div>
    <div class="right"></div>
</div>
</body>
</html>
